/*
 * Copyright 2011-2015 the original author or authors.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package de.schildbach.wallet.ui;

import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.atomic.AtomicReference;

import javax.annotation.Nullable;

import org.bitcoinj.core.Address;
import org.bitcoinj.uri.BitcoinURI;
import org.bitcoinj.utils.Threading;
import org.bitcoinj.wallet.Wallet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import de.schildbach.wallet.Configuration;
import de.schildbach.wallet.Constants;
import de.schildbach.wallet.WalletApplication;
import de.schildbach.wallet.util.Qr;
import de.schildbach.wallet.util.ThrottlingWalletChangeListener;
import de.schildbach.wallet_test.R;

import android.app.Activity;
import android.app.Fragment;
import android.app.LoaderManager;
import android.app.LoaderManager.LoaderCallbacks;
import android.content.AsyncTaskLoader;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.Loader;
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.graphics.Bitmap;
import android.graphics.Color;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.NfcEvent;
import android.os.Bundle;
import android.support.v4.content.LocalBroadcastManager;
import android.support.v7.widget.CardView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ImageView;

/**
 * @author Andreas Schildbach
 */
public final class WalletAddressFragment extends Fragment implements NfcAdapter.CreateNdefMessageCallback {
    private Activity activity;
    private WalletApplication application;
    private Configuration config;
    private LoaderManager loaderManager;
    @Nullable
    private NfcAdapter nfcAdapter;

    private ImageView currentAddressQrView;

    private Bitmap currentAddressQrBitmap = null;
    private AddressAndLabel currentAddressQrAddress = null;
    private final AtomicReference<String> currentAddressUriRef = new AtomicReference<String>();

    private static final int ID_ADDRESS_LOADER = 0;

    @Override
    public void onAttach(final Activity activity) {
        super.onAttach(activity);

        this.activity = activity;
        this.application = (WalletApplication) activity.getApplication();
        this.config = application.getConfiguration();
        this.loaderManager = getLoaderManager();
        this.nfcAdapter = NfcAdapter.getDefaultAdapter(activity);
    }

    @Override
    public void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if (nfcAdapter != null && nfcAdapter.isEnabled())
            nfcAdapter.setNdefPushMessageCallback(this, activity);
    }

    @Override
    public View onCreateView(final LayoutInflater inflater, final ViewGroup container,
            final Bundle savedInstanceState) {
        final View view = inflater.inflate(R.layout.wallet_address_fragment, container, false);
        currentAddressQrView = (ImageView) view.findViewById(R.id.bitcoin_address_qr);

        final CardView currentAddressQrCardView = (CardView) view.findViewById(R.id.bitcoin_address_qr_card);
        currentAddressQrCardView.setCardBackgroundColor(Color.WHITE);
        currentAddressQrCardView.setPreventCornerOverlap(false);
        currentAddressQrCardView.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(final View v) {
                handleShowQRCode();
            }
        });

        return view;
    }

    @Override
    public void onResume() {
        super.onResume();

        loaderManager.initLoader(ID_ADDRESS_LOADER, null, addressLoaderCallbacks);

        updateView();
    }

    @Override
    public void onPause() {
        loaderManager.destroyLoader(ID_ADDRESS_LOADER);

        super.onPause();
    }

    private void updateView() {
        currentAddressQrView.setImageBitmap(currentAddressQrBitmap);
    }

    private void handleShowQRCode() {
        WalletAddressDialogFragment.show(getFragmentManager(), currentAddressQrAddress.address,
                currentAddressQrAddress.label);
    }

    public static class CurrentAddressLoader extends AsyncTaskLoader<Address> {
        private LocalBroadcastManager broadcastManager;
        private final Wallet wallet;
        private Configuration config;

        private static final Logger log = LoggerFactory.getLogger(WalletBalanceLoader.class);

        public CurrentAddressLoader(final Context context, final Wallet wallet, final Configuration config) {
            super(context);

            this.broadcastManager = LocalBroadcastManager.getInstance(context.getApplicationContext());
            this.wallet = wallet;
            this.config = config;
        }

        @Override
        protected void onStartLoading() {
            super.onStartLoading();

            wallet.addCoinsReceivedEventListener(Threading.SAME_THREAD, walletChangeListener);
            wallet.addCoinsSentEventListener(Threading.SAME_THREAD, walletChangeListener);
            wallet.addChangeEventListener(Threading.SAME_THREAD, walletChangeListener);
            broadcastManager.registerReceiver(walletChangeReceiver,
                    new IntentFilter(WalletApplication.ACTION_WALLET_REFERENCE_CHANGED));
            config.registerOnSharedPreferenceChangeListener(preferenceChangeListener);

            safeForceLoad();
        }

        @Override
        protected void onStopLoading() {
            config.unregisterOnSharedPreferenceChangeListener(preferenceChangeListener);
            broadcastManager.unregisterReceiver(walletChangeReceiver);
            wallet.removeChangeEventListener(walletChangeListener);
            wallet.removeCoinsSentEventListener(walletChangeListener);
            wallet.removeCoinsReceivedEventListener(walletChangeListener);
            walletChangeListener.removeCallbacks();

            super.onStopLoading();
        }

        @Override
        protected void onReset() {
            config.unregisterOnSharedPreferenceChangeListener(preferenceChangeListener);
            broadcastManager.unregisterReceiver(walletChangeReceiver);
            wallet.removeChangeEventListener(walletChangeListener);
            wallet.removeCoinsSentEventListener(walletChangeListener);
            wallet.removeCoinsReceivedEventListener(walletChangeListener);
            walletChangeListener.removeCallbacks();

            super.onReset();
        }

        @Override
        public Address loadInBackground() {
            org.bitcoinj.core.Context.propagate(Constants.CONTEXT);

            return wallet.currentReceiveAddress();
        }

        private final ThrottlingWalletChangeListener walletChangeListener = new ThrottlingWalletChangeListener() {
            @Override
            public void onThrottledWalletChanged() {
                safeForceLoad();
            }
        };

        private final BroadcastReceiver walletChangeReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(final Context context, final Intent intent) {
                safeForceLoad();
            }
        };

        private final OnSharedPreferenceChangeListener preferenceChangeListener = new OnSharedPreferenceChangeListener() {
            @Override
            public void onSharedPreferenceChanged(final SharedPreferences sharedPreferences, final String key) {
                if (Configuration.PREFS_KEY_OWN_NAME.equals(key))
                    safeForceLoad();
            }
        };

        private void safeForceLoad() {
            try {
                forceLoad();
            } catch (final RejectedExecutionException x) {
                log.info("rejected execution: " + CurrentAddressLoader.this.toString());
            }
        }
    }

    private final LoaderCallbacks<Address> addressLoaderCallbacks = new LoaderManager.LoaderCallbacks<Address>() {
        @Override
        public Loader<Address> onCreateLoader(final int id, final Bundle args) {
            return new CurrentAddressLoader(activity, application.getWallet(), config);
        }

        @Override
        public void onLoadFinished(final Loader<Address> loader, final Address currentAddress) {
            if (!currentAddress.equals(currentAddressQrAddress)) {
                currentAddressQrAddress = new AddressAndLabel(currentAddress, config.getOwnName());

                final String addressStr = BitcoinURI.convertToBitcoinURI(currentAddressQrAddress.address, null,
                        currentAddressQrAddress.label, null);

                final int size = getResources().getDimensionPixelSize(R.dimen.wallet_address_qr_size);
                currentAddressQrBitmap = Qr.bitmap(addressStr, size);

                currentAddressUriRef.set(addressStr);

                updateView();
            }
        }

        @Override
        public void onLoaderReset(final Loader<Address> loader) {
        }
    };

    @Override
    public NdefMessage createNdefMessage(final NfcEvent event) {
        final String uri = currentAddressUriRef.get();
        if (uri != null)
            return new NdefMessage(new NdefRecord[] { NdefRecord.createUri(uri) });
        else
            return null;
    }
}
